Dual-resolution EnVar capability for HAFS ensemble (#652)

**Description**
Add Dual-resolution EnVar capability for HAFS ensemble
By Xu Lu and Xuguang Wang from OU. POC: xuguang.wang@ou.edu
Fixes #603

**Type of change**
- [Y] New feature (non-breaking change which adds functionality)

**How Has This Been Tested?**
Did a single observation test to ensure the capability works and the
increments look reasonable compared to the single-resolution increment
on Orion.

**Checklist**
- [Y] My code follows the style guidelines of this project
- [Y] I have performed a self-review of my own code
- [Y] I have commented my code, particularly in hard-to-understand areas
- [Y] Any dependent changes have been merged and published

**DUE DATE for this PR is 12/15/2023**. If this PR is not merged into
`develop` by this date, the PR will be closed and returned to the
developer.

---------

Co-authored-by: Bin.Liu <Bin.Liu@noaa.gov>
Co-authored-by: YongzuoLi-NOAA <yongzuo.li@noaa.gov>

src/gsi/cplr_get_fv3_regional_ensperts.f90

@@ -38,6 +38,7 @@ subroutine get_fv3_regional_ensperts_run(this,en_perts,nelen,ps_bar)
   !
   !   2021-08-10  lei     - modify for fv3-lam ensemble spread output
   !   2021-11-01  lei     - modify for fv3-lam parallel IO
+  !   2022-03-01  X.Lu & X.Wang - modify for hafs dual ens. POC: xuguang.wang@ou.edu
   !   input argument list:
   !
   !   output argument list:
@@ -848,7 +849,7 @@ subroutine general_read_fv3_regional(this,fv3_filenameginput,g_ps,g_u,g_v,g_tv,g
     use gridmod, only: eta1_ll,eta2_ll
     use constants, only: zero,one,fv,zero_single,one_tenth,h300
     use hybrid_ensemble_parameters, only: grd_ens,q_hyb_ens
-    use hybrid_ensemble_parameters, only: fv3sar_ensemble_opt 
+    use hybrid_ensemble_parameters, only: fv3sar_ensemble_opt,dual_res
 
     use mpimod, only: mpi_comm_world,mpi_rtype
     use gsi_rfv3io_mod,only: type_fv3regfilenameg
@@ -956,24 +957,24 @@ subroutine general_read_fv3_regional(this,fv3_filenameginput,g_ps,g_u,g_v,g_tv,g
 
 
     if(fv3sar_ensemble_opt == 0 ) then  
-      call gsi_fv3ncdf_readuv(grd_fv3lam_ens_uv,g_u,g_v,fv3_filenameginput)
+      call gsi_fv3ncdf_readuv(grd_fv3lam_ens_uv,g_u,g_v,fv3_filenameginput,dual_res)
     else
-      call gsi_fv3ncdf_readuv_v1(grd_fv3lam_ens_uv,g_u,g_v,fv3_filenameginput)
+      call gsi_fv3ncdf_readuv_v1(grd_fv3lam_ens_uv,g_u,g_v,fv3_filenameginput,dual_res)
     endif
     if(fv3sar_ensemble_opt == 0) then
       call gsi_fv3ncdf_read(grd_fv3lam_ens_dynvar_io_nouv,gsibundle_fv3lam_ens_dynvar_nouv,&
-                            fv3_filenameginput%dynvars,fv3_filenameginput)
+                            fv3_filenameginput%dynvars,fv3_filenameginput,dual_res)
       call gsi_fv3ncdf_read(grd_fv3lam_ens_tracer_io_nouv,gsibundle_fv3lam_ens_tracer_nouv,&
-                            fv3_filenameginput%tracers,fv3_filenameginput)
+                            fv3_filenameginput%tracers,fv3_filenameginput,dual_res)
       if( if_model_dbz .or. if_model_fed ) then
          call gsi_fv3ncdf_read(grd_fv3lam_ens_phyvar_io_nouv,gsibundle_fv3lam_ens_phyvar_nouv,&
-                               fv3_filenameginput%phyvars,fv3_filenameginput)
+                               fv3_filenameginput%phyvars,fv3_filenameginput,dual_res)
       end if
     else
       call gsi_fv3ncdf_read_v1(grd_fv3lam_ens_dynvar_io_nouv,gsibundle_fv3lam_ens_dynvar_nouv,&
-                               fv3_filenameginput%dynvars,fv3_filenameginput)
+                               fv3_filenameginput%dynvars,fv3_filenameginput,dual_res)
       call gsi_fv3ncdf_read_v1(grd_fv3lam_ens_tracer_io_nouv,gsibundle_fv3lam_ens_tracer_nouv,&
-                               fv3_filenameginput%tracers,fv3_filenameginput)
+                               fv3_filenameginput%tracers,fv3_filenameginput,dual_res)
     endif
     ier=0
     call GSI_Bundlegetvar ( gsibundle_fv3lam_ens_dynvar_nouv, 'tsen' ,g_tsen ,istatus );ier=ier+istatus

src/gsi/gridmod.F90

@@ -93,6 +93,7 @@ module gridmod
 !   2019-09-23  martin  - add use_gfs_ncio to read global first guess from netCDF file
 !   2020-12-18  Hu      - add grid_type_fv3_regional
 !   2021-12-30  Hu      - add fv3_io_layout_y
+!   2022-03-01  X.Lu & X.Wang - add corresponding variables for dual ens for HAFS. POC: xuguang.wang@ou.edu
 !
 !                        
 !
@@ -146,6 +147,7 @@ module gridmod
   public :: regional_fhr,region_dyi,coeffx,region_dxi,coeffy,nsig_hlf,regional_fmin
   public :: nsig2,wgtlats,corlats,rbs2,ncepgfs_headv,regional_time,wgtfactlats
   public :: nlat_regional,nlon_regional,update_regsfc,half_grid,gencode
+  public :: nlat_regionalens,nlon_regionalens
   public :: diagnostic_reg,nmmb_reference_grid,filled_grid
   public :: grid_ratio_nmmb,isd_g,isc_g,dx_gfs,lpl_gfs,nsig5,nmmb_verttype
   public :: grid_ratio_fv3_regional,fv3_io_layout_y,fv3_regional,fv3_cmaq_regional,grid_type_fv3_regional
@@ -329,7 +331,7 @@ module gridmod
   real(r_kind) rlon_min_dd,rlon_max_dd,rlat_min_dd,rlat_max_dd
   real(r_kind) dt_ll,pdtop_ll,pt_ll
 
-  integer(i_kind) nlon_regional,nlat_regional
+  integer(i_kind) nlon_regional,nlat_regional,nlon_regionalens,nlat_regionalens
   real(r_kind) regional_fhr,regional_fmin
   integer(i_kind) regional_time(6)
   integer(i_kind) jcap_gfs,nlat_gfs,nlon_gfs
@@ -485,6 +487,8 @@ subroutine init_grid
     update_regsfc = .false.
     nlon_regional = 0
     nlat_regional = 0
+    nlon_regionalens = 0
+    nlat_regionalens = 0
 
     msig = nsig
     do k=1,size(nlayers)